Insulator



Dec. 10, 1940. H, pI SEELYE 2,224,361

' INSULATOR Filed April 26, 1958 2 Sheets-Sheet l H- P. SEELYE INSULATOR Dec. 10, 1940 Filed April 26, 1958 2 Sheets-Sheet 2 Patented Dec. 10, 1940 UNITED STATES PATENT OFFICE y Application April 26,

4 Claims.

The invention to which the following description relates is that of an improved electrical insulator of the type customarily used for supporting electric wiring. Such insulators are widely 5 used where wiring is brought in from a transmission line to a building or the like. Such wiring imposes considerable stress upon the insulator support not only in the direction perpendicular to its base or surface of attachment, but in many instances at wide angles thereto. In such dead-ending an unbalanced strain or tension of considerable quantity is imposed upon the insulator.

Porcelain is an admirable material with which to make such an insulator and in my prior Patent No. 2,050,898, I have shown one form in which such an insulator may be made. There are, however, some conditions in which it is desired to utilize the maximum strength of porcelain as developed when it is placed under compression instead of tension. Consequently, the present invention provides means by which the porcelain of the insulator where it holds the conductor is itself placed under considerable com- 2" pression with consequent increase in strength.

One of the objects of my invention is to provide an insulator having the porcelain maintained under compres-sion with the several metallic members satisfactorily shielded from the 30 electric conductor and protected from exterior exposure.

A further object of my invention is to provide a screw-threaded attaching member by which the insulator may be fastened to its support without the use of special tools and Without imposing exceptional strain upon the porcelain material itself.

Among the objects of my invention is to provide an improved anchor between this screwthreaded fastening and its supporting plate.

Likewise as an incident of my invention my insulator is so designed that its base will be brought up into a tight fit against the support completely shielding the metallic attaching means from exposure or the likelihood of corrosion or current leakage.

Incidental to my design it will be found that the assemblage of the device is rendered more simple and efcient. The above and other advantages will be apparent from the following description of the preferred form of my invention as illustrated in the drawings in which:

Fig. l is a side elevation, partly in section, of the improved service insulator;

Fig. 2 is a plan view of the same;

1938, Serial No. 204,397

Fig. 3 is a vertical section on line 3-3 of Fig. 2; Fig. 4 is a perspective view of the U-bolt and plate;

Fig. 5 is a horizontal cross-section on line 5-5 of Fig. 1;

Fig. 6 is a side elevation partly in section, of a modified form;

Fig. '7 is a Vertical section on line I-I of Fig. 6 and Fig. 8 is a horizontal cross-section on line 8--8 of Fig. 6.

The insulating body member I I of my improved insulator is formed of a single piece of porcelain forming a knob having the desired exterior form and a fiat circular base l2. The exterior of the body member may be of any suitable form facilitating ease in manufacture and serviceability. For this purpose the top may have a transverse saddle I3 and a peripheral groove I4 may be used I as indicated on the drawings.

The electric conductor, wire cable or the like passes through the central transverse passageway I5.

The base I2 has a diametric recess I6 extending in a plane at right angles to the passageway I5. This recess does not intersect the side walls of the body member but on the contrary is completely surrounded by the base I2. A central depression II appears back of the recess I6 for the purpose of holding the head of the attaching screw.

Surrounding the passageway I5 and concentric thereto for half of its periphery is a deep groove I1. The ends of the groove I1 become tangential holes I8 which pass through the body member and into the base recess I6 as shown in Fig. 1.

The recess I6 in the base forms a seat for a cross bar or plate I9. This plate is of less thickness than the depth of the groove I 6 so that when the plate is drawn up against the body member there will be a substantial clearance between the plate and the plane of the base I2. The plate I9 has a central opening 20 through which the shank of the attaching screw passes. This opening 2D may be irregular in shape and in Figs. 4 and 5 is shown to be square so that it may be used to anchor or interlock the shank of the screw. The plate I9 is also provided with openings 2|, 2| registering with holes I8, IB of the body member II. This plate may also be made round or oval.

A strap, band, rod, fillet or the like 22 is provided of ductile metal preferably in the form of a round copper rod. This strap fits in the groove .shown in which the base plate is in the form of I1 with its ends passing through the holes I8 and into the recess I6. The ends 23 of the strap 22 pass through the plate I9 and are headed, riveted or swaged into the plate or bolted thereto so that the latter can be drawn tightly up against the body member II.

It is to be understood tha-t prior to the attachment of the strap 22 the Wood screw 24 has been inserted through the plate I9 with its head 25 above the plate- I9 and received in the depression I1.

The shank of the wood screw has diametric ribs 26 which anchor into the corners of the square opening 20 and prevent relative rotation of the screw and plate. To facilitate assembly and .insure the proper positioning of the parts, these ribs 26 may be formed as tangswhich are bent over the lower face of the plate. I9 as shown in Fig. 1.

In Figs.r 6, '1 and 8 an alternative` form. is

strap'224 is passed beneath the base plate I9 or 21 and the ends 23 upset, headed or otherwise swaged. This tends to bring the head of the screw into contact withy the body member and toy lift the bottom surface of the base plate I9l or 21.above the plane of the basev I2.

An insulator of this type is readily used as it can be driven with considerable force against the support without damage to itself. It may then bel rotated causing the torsion to be applied to the screw through the extended base plate I9 or 21. This avoids reliance upon the porcelain for localized torsion. In the nal tightening of the screw the porcelainv base I2 is brought against the support andtheporcelainbody member thus placed under preliminary compression. When thewire conductoror cable is attached the porcelain of thefpassageway I5 isplaced under further compression resulting in the greatest strength and durability. The direction. of approach of the conductor isl relatively unimportant and has slight if any effect upon the strength ofthe insulator.

While' I have-shown' the preferred form of the invention it is to be runderstood that thishas been done by way of' example only andthatfminor changes'in the design and material may-be made without departing fromy the scopev of the invention as defined in' the'followfing" claims;

a plate in said recess spaced wholly above the plane of the base, a strap in said openings and groove with its ends fastened to the plate, a central irregular opening through the plate, a screw extending through said last named opening and means on the' shank of the screw for interlocking with said opening.

2; An insulator having an insulating body i member with a base with a nat surface and a transverse wire-holding passageway, a groove in the member aboveand concentric with the transverse passageway, openings. through the member oneach side of the transverseA passageway connectingthe groove with the base, a diametric recess in the base extending between the openings but not through the sides of the member, av channeled plate in said recess, a strap in said openings and groove with its ends fastened to the plate, a central opening through the plate, and a screw extending through said opening, said screw having a polyhedral head anchored in the channel of said plate. y

3. An insulator having an insulating body member with a base with a flat surface and a transverse wire holding passageway, a groove in the member above and concentric with the transverse passageway, openings through the Inember on each side of the transverse passageway connecting the groove with the base, a diametric recess in the base extending between the openings but not through the sides of the member, a plate in said recess and spaced wholly above the plane of the base, a strap in said groove and openings with its ends fastened to the plate, and a screw anchored in said plate. y

4; An insulator having an insulating body member with a base with a lat surface and a transverse wire holding passageway, a groove in the member above and concentric with the transverse passageway', openings through the member on each side of the transverse passageway connecting thev groove with the base, aA diametric recess in the base extending between the openings but not through the sides of the member, a plate in said recess and in Contact with the side walls of the recess, a strap in ysaid groove and openings with its ends fastened to the plate, and a screw anchored to said plate;

` HOWARD P. SEELYE. 

